It's an improvement, but its not quite there yet.
The campaign is alright. I seem to get 30 fps in some spots (this PC can max out BF3, it cant be my comp) and the gameplay is alright. The story is pretty good though, unlike most COD games.
The multiplayer is as great as ever. Aside from the fact that they f'ed up the Nuketown 2025 mode, which is the only mode I really play.
I don't really see a variety of guns, but the guns that are there are pretty good.
But one downside is the fact that shotguns are so overpowered, and hit detection is horrible. I get killed by someone who wasn't even close to killing me.
Another negative part about this game is the servers. Oh my god, they are crap. I play on PC, people are lagging left and right. It's worse now than it was on launch. Wtf, Treyarch? Get this fixed ASAP. It's almost as bad as BF3's servers.
But on the bright side, sniping is much easier. I'm not the sniping type at all, except for Black Ops 2. I can get a 7 kill streak without even trying. Maybe a bad thing for some people, but I personally love the change.
I don't really like the futuristic style though. I prefer using an AK47 over the majority of weapons in blops 2. I really hope Infinity Ward doesn't follow this trend.
This game is definitely worth a buy, aside from a few of my problems. It's overall a fun game, I just don't like the futuristic aspect a whole lot. The game in general is fun, but I don't feel like I'm playing Call of Duty.